Rocky, I had that same issue when I first ran my sluice and it took a little bit to figure out what I needed to do. Having the water run over the edges of the sluice will lose gold because it means the water isn't flowing through the sluice in a straight pattern and that external water forces can affect the flow from the outside, less water would be coming in from the feeder end because the water would be flowing from the sides affecting the whole process essentially. To fix this I would recommend you set your sluice in an area that has a natural dip in the water, if the water is flowing flat your sluice will be a lot harder to set and you would need to build up a foundation that allows the water to dip naturally to do so.

That's what I thought I'd hear. Much appreciate the feedback. I just had to purchase a bilge pump to remove the water settled on the pool cover before it can be removed. If I'm going to keep sluicing the same stream guess I should setup some sort of recirculation system using the new bilge pump then.

look up Wing Dam on You tube

you need to make up a wing dam in the front of the sluice and raise the front so the sluice has a pitch and the water is running through the sluice until it exits at the end.

I bought and have used a Sluice Stand in the river and that helps me set it up a bit faster when you are in an area where there is some kind of rocks damming it up and slowing down the water flow.

let the water move the material for you - you do not need a pump as nature is better than all - if you need more flow, use a steeper pitch but use a wing dam in the front of the sluice to drive the proper water flow to your box and then work on the pitch to go through the box and not over the sides or have the bottom submerged in the water as all the rocks will clog up in the bottom of the box

keep the box bottom with the material dropping out or leaving cleanly - if it is clogging up, steepen the pitch or increase the water flow with the wing dam

good luck